Heart transplantation (HT) is a lifesaving procedure for patients with end-stage heart failure and provides a better survival and quality of life if compared to medical treatment. HT is subject to alloimmune response, which, if left uncontrolled, is capable of jeopardizing long-term cardiac function. Advances in immunosuppression have enhanced the survival of HT patients. Nearly 2500 HT per year have been performed in the US during the last 10 years and despite significant improvements, long-term survival rates remain poor. More than 20% of patients do not survive more than 3 years, and those who survive are afflicted by long-term complications of alloimmunity and chronic immunosuppression. Life expectancy of patients who lose cardiac allografts is dramatically poor due to the absence of any therapeutic tool apart from re-transplantation, which is plagued by poor outcomes. The identification of novel therapeutic targets is thus mandatory. ATP/P2X7R signaling in T cells is highly relevant for cardiac allograft survival. ATP is a small molecule present at high concentrations inside cells; it is released as extracellular ATP (eATP) following cell damage or death where it acts as a danger signal. ATP is sensed by the P2X receptors (seven receptors named P2X1-7), mainly expressed by T lymphocytes. We have recently demonstrated that the ATP/P2X7R axis has a key role in cardiac allograft survival in humans and mice. Cardiac allograft vasculopathy (CAV) is a major limiting factor for HT survival; indeed CAV occurs in 50% of HT recipients by 5 years after transplantation and invariably results in allograft failure. CAV is clearly of immunological origin, as syngeneic murine grafts do not develop it. Once CAV occurs, the most definitive treatment is re-transplantation, but survival remains poor. We hypothesize that a single nucleotide polymorphysm (SNP) loss-of-function P2X7R mutation (p.Glu496Ala / c.1513A>C, rs3751143) generates a compensatory upregulation of the other purinergic receptors (P2XsR), thus creating a state of hypersensitivity to eATP. This eATP hypersensitivity results in an abnormal generation of Th1/Th17 cells, that leads to CAV and early cardiac allograft loss. Our study will answer a fundamental question: What is the effect of the P2X7R loss-of-function mutation on the immune system? Our goal is to generate the first targeted-therapy for a selected group of cardiac transplant recipients.

NCT02082821

Conditions

1. Cardiac Allograft Vasculopathy

MeSH:Vascular Diseases

We hypothesize that a single nucleotide polymorphysm (SNP) loss-of-function P2X7R mutation (p.Glu496Ala / c.1513A>C, rs3751143) generates a compensatory upregulation of the other purinergic receptors (P2XsR), thus creating a state of hypersensitivity to eATP.

Loss-of-function single nucleotide mutations (SNPs) have been detected for P2X7R gene; particularly the Glu496 to Ala 1513A>C (rs3751143) P2X7R loss-of-function mutation is relatively common (1-3% of individuals are mutated omozygous and 25% are heterozygous).

To test this hypothesis, we will follow two main paths: i) we will evaluate in the CTOT-05 cohort of cardiac transplant recipients the effect of the Glu496 to Ala 1513A>C (rs3751143) P2X7R loss-of-function mutation on clinical end points (development of coronary artery vasculopathy, death, re-transplantation or re-listed for transplantation, any rejection) in the first year post transplant; ii) we will explore in vivo and ex vivo in the CTOT-05 cohort of cardiac transplant recipients the effects of P2X7R loss-of-function mutation on the immune system.

Depression is one of the most important causes of disability in the world today, with major personal, social and economic costs. Although some moderately effective drug treatments are already available, about a third of patients with major depressive disorder (MDD) remain depressed despite current treatment. There is growing evidence that inflammation - the response of the body's immune system to physical and social stresses - can cause depressive symptoms in some patients. It is therefore predicted that anti-inflammatory drugs could have anti-depressant effects and the research team aims to test this using a new drug, JNJ-54175446, which blocks the activity of a receptor called P2X7. P2X7 is present on many immune cells and plays a key role in the release of inflammatory molecules during stress, which may be linked to stress-related depression. The research team will recruit approximately up to 142 participants with MDD to this clinical trial. Patients will have moderate-severe depressive symptoms despite ongoing treatment with a conventional anti-depressant drug, and they will have blood test results at screening that indicate they are likely to have active P2X7 signalling in the brain. Eligible participants will be randomly allocated to receive either 50mg/day JNJ-54175446 or placebo for 8 weeks. Participants will be assessed at weeks 2, 5 and 8 using a standard clinical depression scale and the scores compared between those treated with placebo and those treated with JNJ-54175446. To understand more about the effects of JNJ-54175446 on the immune system and the brain, patients will also complete additional blood tests, questionnaires and magnetic resonance imaging (MRI) brain scans at different visits throughout the trial. The trial will be carried out across 5 centres in the UK.

NCT04116606

Conditions

1. Depressive Disorder, Major
2. Inflammation

Interventions

1. Drug: Active JNJ-54175446
2. Drug: Placebo

MeSH:Inflammation Depressive Disorder Depression Depressive Disorder, Major

HPO:Depressivity

3. Presence of two copies of the loss-of-function C allele at rs3751143, and/or has one copy of the loss-of-function A allele at rs1653624 in the P2RX7 gene.